251972 ÷ 20 
The aim is to understand the frequency of 20 in 251972.

Moving on to step 1:
20 can be fit into 2 0 times, resulting in a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Grab the next digit (5) from the dividend, add it to 2, then carry on: 25 / 20

Going ahead to step 2:
If we divide 25 by 20, we get 1 and a remainder of 5.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 5 after subtracting 20 from 25.
Take the next digit (1) from the dividend and append it to 5, then repeat: 51 / 20

Advancing to step 3:
The number 20 fits into 51 2 times, leaving a remainder of 11.
Put 2 as the next digit of the answer. 
Result so far: 12.0
Subtracting 40 from 51 leaves us with 11.
Append the next digit (9) from the dividend to 11 and continue with: 119 / 20

Step 4:
20 goes into 119 5 times with a remainder of 19.
The next digit of our result is 5. 
Result so far: 125.0
Subtracting 100 from 119 leaves us with 19.
Include the next digit (7) from the dividend after 19, then repeat: 197 / 20

Step 5:
The number 20 fits into 197 9 times, leaving a remainder of 17.
Write down 9 as next digit of the result. 
Result so far: 1259.0
The remainder is 17 after subtracting 180 from 197.
Grab the next digit (2) from the dividend, add it to 17, then carry on: 172 / 20

Going ahead to step 6:
20 can be fit into 172 8 times, resulting in a remainder of 12.
The next digit of our result is 8. 
Result so far: 12598.0
Deduct 160 from 172 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 7:
120 divided by 20 is 6 with a remainder of 0.
Use 6 as the next digit of our solution. 
Result so far: 12598.6
Subtracting 120 from 120 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 8:
If we divide 0 by 20, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 12598.6
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 9:
If we divide 0 by 20, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 12598.6
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 12598.6 with a remainder of 0.0.